Tabulator rebound trap



March 14, 1933. F` P GORlN 1,991,096

TABULATOR REBOUND TRAP Filed Aug. 1l 1928 3 Sheecs-Sheesl l arney March14, 1933. F, P GOWN 1,991,096

TABULATOB. REBOUND TRAP Filed Aug. l1 1928 3 Sheets-Shet 2 INVENTOR mmh14, 1933. F, P, @om 1,901,096

TABULATOR REBOUND TRAP Filed Aug. ll 1928 3 Sheets-Sheet Z Jfyz l Jg. l!

INVENTOR lil Patented Mar. 14, 1933 FREDERICK P. GORIN, OF SEATTLE,NASHINGTON, ASSIG-NOR T10 GORIN SHOCKLESSPEED TABULATOR- COMPANY, OFKING COUNTY, VTASHINGTON TAIBULATOR REBOUND TRAP Application filedAugust 11, 1928. Serial No. 299,082.

This invention relates to improvements in typewriting machines and moreparticularly to the tabulating mechanism. The principal object of theinvention is to generally improve upon the constructions shown in thevarious patents heretofore issued to me, and particularly theconstruction shown and described in Patent 1,411,997 issued to me on thefourth day of April 1922, in which I showed, described. and claimedmeans to positively prevent rebound of the carriage past thepredetermined writing point. All of the said patents require (a) that acarriage buffer be employed, because, in the said patents, it isnecessary that the carriage passbeyond the pre-determined writing pointand be returned thereto under the reflex action of the carriage buffer,in order to cause the setting' or springof the rebound lock. In otherwords, in all of the said patents, the rebound lock would be inoperativeand useless if no carriage buffer were employed. ln the presentinvention it is optional whethera carriage buffer l be employed or not`the rebound being effectually prevented in either case, because, in thepresent invention the rebound lock is, as is also true regarding all ofthe said patents, normally unset or unsprung, but, in the presentinvention, means are provided which causes the instantsetting orspringing of the rebound lock upon the operation of a tabulator key,whereas in all of the said patents the lock remains unset until thecarriage has completed its run to the printing' point.V The result ofthis is that in the presentV invention the carriage, -even in itsshortest run, cannot possibly rebound away .from-the pre-determinedprinting point. (b) In all,` of the said patents, it sometimes happens,that the run of the carriage in a tabulating operation is so short thatthe blow resultant upon the impact of the tabulator stops with eachother is not suiiicientto completely and securely set the rebound lock,even though the blow be Y sufficient to cause the carriage to passslightly beyond the writing` point and be returned thereto by the reflexaction of the carriage buffer. This defect is completely cured in the`,resent invention because it is not necessary that the carriage passbeyond the writing point at all, as already stated. If the readerconsult the disclosure ofthe said Patent No.

1,411,997 and compare it with this disclosure,`

it is thought the difference will be perfectly plain to him. y In thedrawings:

F ig. 1 isa rear elevation of the well known,

Elliott Fisher `typewriting device applied thereto. Y

Fig. 2 is sectional view of 'my device machine with taken on the line2-2of Fig. 1, showingthe parts in their normalpositions.

Fig. 3 is a similar view showing the positions of the parts j ust afterthe tabulator key has'been actuated, the letterfeed disengaged, andbefore the impact of the tabulator stops with each other. y

Fig. 4 is a view partly in section taken upon the line 4 4 of Fig. 1,and showing the parts in their normal positions as in Fig; 2. Y

5 is a similar view showing the posi'- tions which the parts assumeafterthe tabulator stops have collided with each other.

Fig. 6 is a perspective view of the toothed locking apron. i i Y 1 Fig.7 is an enlarged fragmentary view showing the arrangement 0fthe buffersprings.v 1" i Fig. 8 is a similar viewenlarged sufliciently to show theaction of the toothed apron with respect to the locking stud, and alsothevpeculiar formation of the stud. g fj v F `9 is a similar viewshowing the position of the locking bail after the stops `have collidedwith each other.

Fig. 10 is a cross sectional view taken on the line 10-10 of Fig. 1. f fFig. 11 is a fragmentary plan view showing the arrangement of the dashpot mechanism. Fig. 12 is a fragmentary view of the carriage feedingmechanism. A v

My device is shown inthe drawingsas at tached to the well known ElliottFisher type- V'writing machine, although it will be understood that thedevice can be attached to, or

vmade a part of, any other, form of typewriting machine which involves aframework and a carriage movable thereon. lReference numeral 1 marks thecarriage; 2, the framework or bed; 4, the usual rolling frame haveinening wheels 5 which run upon tracks 6 extending longitudinally of thebed; 7, the traction wheels upon Vthe carriage 1 which roll upon tracks8 upon the yrollingv frame, whereby the carriage has a transversemovement upon the rolling frame and the rolling frame in turn has alongitudinal movement with respect to the bed. 9 marks the wires whichconnect the rock shafts 1() with the usual type levers (not shown). Eachof the rock shafts has an out-turned end 11 (Figs. 2 to 5) to which isconnected a link 12 which in turn is similarly connected to one of thetabulator plungers'13, pivoted at 14 to a housing 15, so that anoperation of one of the usual type leverscauses its correspondingplunger to move about its` pivot whereby itsnose 16 is projected intothepath ofthe tabulator stops 17, to arrest the carriage in a tabulatingAmovement, the plungers being returned to their normall positions,against a limit stop 1S by springs 19 and 20. 21 marks the usual crossbar universally acted upon by all the plungers 13. 22 is the usualspring motor drum connected to the `carriage by a tape 23. 24 is theusual casting secured to the carriage by vscrews 25 (Fig. 12) andwithinwhich is mounted the feed wheel 25-Y-a having teeth 26 with which'coacts the feed pawl 27. The position of the pawl when a tabulator stop17 is in contactwith a projected plunger 13, during a tabulatingoperation, is shown in dotted lines (Fig. 12). 28 indicates the usualtabudotted lines (Fig. 1), two

liott Fisher typewriting machine. l

4 Secured by screws 28e-a at each side of the rolling frame 4, areL-shaped brackets 29 upon which are mounted blocks 30, which arepermitted a slight rotative ymovement by reasonV of screws 31 which passthrough the blocks and into the brackets (Figs. 10 and 11). Thisrotative movement of the blocks is provided so that the blocks will keepin perfect Y. alignmentV with each other for a purpose Qwhich willpresently appear.

The blocks are channelled to receive bars 32 which slid-e within thechannels. 33 are keeper plates for the bars, firmly secured to theblocks by screws 37. 34 marks an extension having up-turned ends 35(Figs. 10 vand 11), one of which is firmly secured at 36 to the'-rolling frame and the other is ldrilled and tapped toV receive a screw37-5 which firmly secures to it` a dash pot'38 having a mushroom valve39 interposed between two Y washers 40 which are in turn firmly securedto the outer end of one ofthe bars 32, by means of a screw 41. TheeXtreme left hand end (Figs. 1 and 11) of that bar is secured by` ascrew 42 to a bracket 43 which is Vmilled across Vits undermost surfaceso as to leave lugs44 (Fig.2) which straddle the usual tabulator stopbar 45, aser-ew 46 serving to firmly f ends of the brackets bindrthebracket 43 to the stop bar. The foregoing describes the manner ofslidably mounting the stop bar at its right hand end (Fig. 1) upon therolling frame and the saine also describes the manner of mounting thesecures to that bracket one end of a main carriage buffer spring 48, theopposite end of the buifer spring being secured at 49 to one end of ascrew threaded shaft 50 having a head 51 at one of its ends, and whichslidably passes-through an aperture 52 in a guide plate 53, secured by ascrew 54 to the rolling frame (Figs. 1 and 7 55 is a downwardlyprojecting extension rigid with the lefthand bracket 43v (Figs. 1 and 7)and which is smoothly bored to allow the threaded shaft 50 to slidablypass through the bore. 56 is a supplemental carriage buffer spring whichis much weaker than the main buffer spring. The supplemental Vbufferspring is confined between ya thread-ed nut 57 mounted upon the shaft50, the nut being free to move with the shaft from its position as seenin Fig. 7 until it contacts with the plate 53. Threadedly mounted uponthe shaft 50 is a small washer 58 having apertures 59 to accommodate theend of a wire or other like instrument which may be thrust through theapertures so as to l3- allw the small washer to be turned to advance iteither one way or the other along the shaft to any desired position.From this arrangement it will be seen that when the stop bar be thrustto the left and the carriage held tent as to completely collapse it andthus cause it to become set or to lose its life and elasticity.

60 indicates brackets (Figs. 1 and 2) one rigidly secured upon each sideof the plunger housing15 by means of screws 61, the upper receive apintle 62 (Figs.` 1 and 2). Upon kthe pintle is swingably mounted anapron 63 having ratchet teeth 64. A spring 65 is coiled around thepintle (Fig. 3). One of the ends of the spring is secured at 66 to oneofthe brackets and its opposite end bears upon the apron as at 67 (Figs. 1and 5), so that thetoothed edge of the apron is normally urged inclockwise direction (Fig. 2) about the center represented by the pintle.

being bored through to shaped bracket 29, (Fig. 1) is a hook 47 which Ylli) above it corresponding to Pivoted at 68 to the toothed apron is atrigger 69 (Fig. 4) andv bearing upon it is one end of a leaf spring 70(F ig-s.4 4 and 5) its opposite end' being secured at 71 to the innersurface'of the apron 63 (Figs. 4, 5 and? 6) so that when. th-e parts arein their normal positions as seen in F ig; 4, the trigger holds theapron in the position as seen in that iigure, so that the carriage isfree to be moved in either direction. It will be understood thatl theleaf spring 70 is` very much. weaker than the coiled spring 65 and itsfunction is to always urge the trigger 694k towards its position as seenin F ig. 4. Z2is a bail having its upturned ends73 pivoted at 74 to thebrackets` 43 (Fig. 4). The bail drops by gravity to its normal positionas seen in full lines in Figs. 2 and 9. Each of the tabulator plungers13 is notched as at 7 5 (Figs. 2 and 5). 7 6 is a cam member secured byscrews 77 to one of the L-shaped brackets 29 (Fig. 9). Each of the usualElliott Fisher tabulator stops 17 is provided with an upstanding stud 78 (Figs. 7 and 8) which is normally out of the path of the teeth 64 ofthe apron 63T but which areadapted to co-act with those teeth when atabulator stop 17 collides with a projected plunger 13, as will now bedescribed.

Operation Whenever one of the usual Elliott Fisher tabulator keys 28 bedepressed to release the usual Elliott Fisher letterfeeding mechanism(Fig. 12) with a simultaneous projection ofl a corresponding tabulatorplunger 13, and a resultant movement of the carriage in letter-` ing theoperation of the tabulator key 28, the i rebound locking mechanism wasset, the parts assuming their positions as seen in Fig. 3. From aninspection of Fig. 4 it will be seen tha-t the trigger 69 is'substantially in the shape of a human foot, the lowermost point of thetrigger corresponding to the toe of the' foot and the point or cornerimmediately the heel. A line drawn from the point of contact of the heelwiththe bracket 60 to the pivot 68 of the trigger, as these parts appearin Fig. 4, is.

much shorter than a similar line drawn between these points as the partsappear in Fig. 5. That is to say, as the trigger is rotated about itspivot from the position shown in Fig. 4 to the position shown in 5 7 thedistance between the bracket 60 and the y apron 63 necessary to bespanned by the tri gger in order to prop up or hold the apron teeth 64out of the plane of the stud 78 creases and, since the dimensions of thetrignism is set by reason of the swinging forv ward of the plungers 13to the position shown inF ig. 5f which of course move the bar21 with it,by reason of the fact that the bar 21 extends across the front faces ofall the plungers. The cross bar normally lying behind the trigger 69will ofcourse cause the trigger' to move across its center 68 from itsFig. V4 position to its Fig. 5 position, with a. resultant movement ofthe trigger 69 in clockwise; relation to .the position seen in Fig. 5 byvirtue of the heavy spring 65 about the pivot 62.v

When the tabulator key '28 was operated, the feed pawl 27 was caused tomove from its full line position to its dotted line position in Figure12, allowing the carriage to move-freely in letterfeed direction, asusual in any tabulating` operation. This movement continues untiltheplunger 13 collides withthe tabulator stop 17. Before the instant ofthis collision, the carriage with its apronV has been moving freely' inletterfeed direction, but the collision of the plunger 13 with the stop17 causesthe carriage to pick up stop bar 45 and from that time on thecarriage, apron, stop bar and stud are all moved on together inletterfeed direction beyond. the point of collision and against theaction of the buifer spring. Before said collision of the stops, theteeth 64 irst collided with the studs 78I but theapron freely chatteredor rolled over the stud 78 until the collision of the plunger 13 and thestop 17 occurred. At that time, the teeth 64 assumed the dotted lineposition shown in Figure` 8 and then all the parts just enumerated movedon together..

On the reflex action of the buffer spring,all i these parts werereturned together in centraletterfeed direction to the point where thecollision of the tabular stops took place, that is, the printing point,and when they'were so returned, the partswere all in their operativelpositions.

All the parts enumerated have now made a complete excursion from theprinting point to the left in Figure 8 and back to the print-y ing pointand no farther, because the stop rod cannot be moved farther to theright for thereasonthat it is now against its limit stop in thatdirection, that is, the block 30, and neither can the carriagel be movedfarther to the right because of the teeth 64, as already explained. Thecarriage has n ow been returned to the printing point by the action ofthe buffer spring 48 of the carriage, lbut the rebound trap Visvnot yetunlocked or unset but, on the contrary, is still firmly locked andcannot possibly become unlocked until the carriage again starts tomoveto the left Figure 8), that is, in letterfeed direction. Thus. ofcourse, the carriage is now free to do for the distance of about oneletter space only because the pawl 27 is sure to be caught by the notchon the feed wheel which is just to the left of the pawl inFigure l2.This letter space movement of the `carriage is clearly suficient tocause the tooth 64, which is just to the vright of the stud 7 S (Figure8) to ride up freely upon the cam face oi: the stud 7 8 until it reachesits ull line position (Figure 8).

This upward movement of the apronl 63 permits the trigger 69 to returnto its normal position, as shown in Figure 4, until Va subsequenttabulating operation. The carriage is now free to be moved in eitherdirect-ion because the apron 63 isin the position indicated in fulllines in'Figure 8 and will not, ot course, interfere with carriagemovement in either direction. The carriage, by this time, comes againunder control of its motor mechanism, which draws the carriage again inletterfeed direction and causes the tooth of the apron, which 'had beenin engagement with the stud 78, to ride up over the stud in -letterfeeddirection from its position as Vshown in dotted lines to its position asseen in full lines in Fig.` 8, permitting the trigger. 69, the projectedplunger, the bail and other parts to return to their normal positions asseen in Figs. 2 and l and allowing the carriage to move. one letterspace in letterfeed direction (Fig. 12) and the letterfeeding mechanismto re-engage at that exact point.

It will be noted that the stud 78 (Fig. 8) is of approximately the samecontour -as the teeth 64 of the apron63 withthe exception that the studdoes not represent a true point asdo the teeth, but is chamfered ofi' asplain.v

ly shown; The result of this is that if, due to wear, inaccurate shopwork, or the like, the trigger 69 should in time fail to prop or holdthe apron 63 in its position as seen in Fig. t, thus allowing the'teethof the apron to .de-

scend slightly below theV plane of the top of the stud, thenthe'chamfered portion of the stud will allow the teeth of the apron tofreely pass to the right by a corresponding movement of the carriage,(Fig. 8) the stud offering no interference, because the apron teethwould ride over the small cham'fered edge of the stud.

I have shownthatthe rebound lock effectively traps the carriage andprevents rebound when the carriage cushion be employed, and

it is obvious that the carriage will be trapped in exactly the samemanner Vand rebound rendered impossible when the 'carriage cushion, dashpot, bail and the notches in the plungers, be dispensedwith. In suchcase the tendency of the carriag-e to rebound follows immediately uponthe Vimpact of the tabulator plunger with thel tabulator stop,- whereaswhen a carriage cushion be employed the tendency to rebound occurs aninstant after such impact. However, in either case,

rebound is impossible because the rebound trap is set before the impactand the carriage permitted to move one step in letterfeed directionafter the tabulator plunger has freed itselic from the tabulator stop.In the use of a carriagey cushion there is no time lost because theoperator continues pressure upon the tabulator key until the tabulatorplunger and stop collide with each other, just as is usual in alltabulating operations, and eX- perimental proof has shown that the timerequired or a rapid operator to move the hand from the depressedtabulator key to the selected type or character key, and to depress thatkey its full stroke so as to carry the type into contact with thepaper,-is considerably greater than the time required for the cushion tofunction and allow the carriage to come to complete rest at the writingpoint. I prelier, of course, to use a carriage cushion, but incorrespondence typewriting machines of relatively small cost and havingrelatively light carriages, the cushion may be dispensed with, ifdesired. Y

I claim:

l. In a typewriter, tabulating mechanism, a rebound preventing trap,means independent of the movement of the typewriter carriage 'forsetting the trap, and automatic means which insures the maintenance ofthe trap in a set condition after the carriage is ,arrested by thetabulating mechanism and until the carriage resumes its letterfeedtravel after such arrest. l

2., In a typewriter,tabulatingmechanism, a rebound preventing trap,means independent ot the movement of the typewriter carriage Jforsetting the trap, automatic means which insures the maintenance of thetrap in a set condition after the carriage is arrested by the tabulatingmechanism and until the carriage resumes its normal letterfeed travelafter such arrest, and a builer for the carriage.

3. In a typewriter, the combination of a the trap, and means whichinsures the unset- 'ting of the trap only after ythe arrest of thecarriage by the tabulating mechanism and ollowingthe letterfeed travelof the carriage immediately after suchy arrest.

il. In a typewriter, tabulating mechanism, a carriage rebound trap,means for setting the trap, and means acted upon by the carriagemovement in letterieed direction to unset the trap.

5. In a typewriter, tabulating mechanism, a carriage rebound trap, and`means for setting the trap, the said trap comprising means acted upon bythe carriage movement in letterfeed direction only to unset the trap.

6. In a typewriter having a frame and a carriage movable thereon,Vletterfeeding mechanism, a carriage cushion and means including arebound preventing trap which takes complete control of the carriagemovement when the carriage reaches the printing point in a tabulatingoperation, said means maintaining such control without manual assistanceuntil the carriage is momentarily arrested by the rebound preventingtrap at the printing point preparatory to the iinal arrest of thecarriage at that point by said letterfeeding mechanism.

7. In a typewriter having a frame and a carriage movable thereon,letterfeeding mechanism, a carriage cushion, means which includes arebound preventing trap mounted partly on the carriage and partly on theframe, which takes compl-ete control of the carriage movement when thecarriage reaches the printing point in a tabulating operation andcontinues such control without manual assistance until the carriage ismomentarily arrested at the printing point by said rebound preventingtrap preparatory to the iinal arrest of the carriage at that point bythe letterfeeding mechanism.

8. In a typewriter tabulating mechanism, a rebound preventing` trap,means for springing the trap immediately following an actuation of atabulator key incident to the operation of the tabulating mechanism, andmeans which insures the unspringing of the trap at the printing point asa result of the letterfeed movement of the carriage only.

9. In a typewriter including step by step letterfeed mechanism,tabulating mechanism including stops, a rebound preventing trap, meansfor setting the trap following the ac- 05 tuation of a tabulator key,means which preserves the trap in a set condition independent of anyfurther actuation of the tabulator key, and means acted upon by theletterfeed movement of the carriage to unset the trap. 40 l0. In atypewriter including step by step letterfeed mechanism, tabulatingmechanism including stops and tabulator keys,a carriage buier, a reboundpreventing trap, means for setting the trap following the actuation of atabulator key, Vmeans for preventing the unsetting of the trap until thecarriage reaches the printing point in a tabulating operation, and meansacted upon by the letterfeed movement of the carriage to 59 unset thetrap.

In testimony whereof I affix my signature.

FREDERICK P. GORIN.

CII

